11L On the Variation of the Barometer.

Having now endeavoured to explain the prin-cipal facts relative to the variation of the baro-meter, we shall next advert to some other par-ticulars on the subject, which tend to illustrateand confirm the doctrine we have advanced.

The barometer generally rises with a wind be-twixt the north and the east ; it rises very highduring a long and uninterrupted frost ; it washighest for the last 5 years in January 1789;the mean temperature at Kendal, for 4 weekspreceding, was 28°, which was lower than forany other similar interval in the 5 years ; therewas only 1-643 >uches of rain and snow for 7weeks before; these were clear proofs of theprevalence both of cold and diy air.

The barometer is often low in winter, when astrong and warm S. or SW. wind blows ; theannual extremes for these 5 years have alwaysbeen in January; the lowest was in January,1789, about 2 weeks after the above mentionedhigh extreme; it was accompanied with a strong8 or 8W. wind, and heavy rain; the tempera-ture of the air at the time was not high, beingabout 37 0 , but the reason was no doubt becauseone half of the ground was covered with snow;it was therefore probably warmer above—Nowthe reason why the low extreme should have atthat time, as well as at many others, soon suc-ceeded the high extreme, seems explicable as

follows: